Chemical sampling apparatus



Dec. 16, 1969 H. LOEBL 3,484,206

CHEMI CAL SAMPL ING APPARATUS Filed May 5, 1966 2 Sheets-Sheet 2 F/G. 3. I

2 l 23 (5/ O O O O O U 0 O O U 0 H O O O O O United States Patent M 3,484,206 CHEMICAL SAMPLING APPARATUS Herbert Loebl, Newcastle-upon-Tyne, England, assignor to Joyce, Loebl and Co. Limited, Gateshead, England, a British company Filed May 3, 1966, Ser. No. 547,290 Claims priority, application Great Britain, May 7, 1965, 19,306/ 65 Int. Cl. G01n 33/16 US. Cl. 23253 2 Claims ABSTRACT OF THE DISCLOSURE To prepare samples in the order of fractions of a milliliter for centrifuging, a plurality of sample receptacles are intermittently brought into registration with a pipette held on an arm; the pipette is dipped into each receptacle in turn, to extract fluid therefrom, the pipette being located such that it is guided during withdrawal from the receptacle in a path over the edge of the receptacle in order to wipe off any droplets carried by the pipette, the samples subsequently being deposited in a tubular receptacle located on a ring and inclined along its longitudinal axis.

Our invention relates to improvements in chemical sampling apparatus and more particularly to apparatus for receiving a series of samples of chemical substances such as body fluids and transferring them with or without the addition of a reagent or cleaning fluid to a series of receptacles in sequence.

Our invention is especially concerned with apparatus for the treatment of samples or biochemical fluids obtained from patients in a hospital. The fluid from each patient is drawn off into a tube or trough which is labelled in suitable fashion with the identity of the patient. The said tubes are placed in sequence in a container or support, and the container is then placed in an apparatus adapted to contain a further container loaded With receptacles, Whereafter the containers are moved by equal amounts so that a sample can be transferred from a tube or trough to a receptacle or several receptacles by an automatically operated pipette or pipettes.

Each pipette dips into the sample tube and extracts a predetermined quantity of fluid therefrom. The pipette then rises from the tube and moves over to its receptacle, the rate of discharge being such as to mix the sample and reagent thoroughly, and clean out the pipette.

Alternatively, the pipette may remove a supernatant sample from a receptacle and transfer it to a further receptacle, add a predetermined quantity of one or more reagents, or transfer fluid to a measuring device, the action being determined by the process to which the sample is to be subjected or has been subjected.

The apparatus comprises a rotating stage or table adapted to support a ring or rings and rotate them in steps, each step being of such length as to bring the containers and/or receptacles one after another into the path of the pipette movement. The apparatus is preferably driven by an electric motor controlled by registering contacts associated with the ring, and the rate of rotation of the ring is predeterminable. The motor operates the pipette, by means of a cam shaft.

Instead of a container or ring, a long table or an endless belt or like device may be used if a large number of samples is required to be processed.

In one embodiment we terminate the pipette with a short length of small-bore flexible tubing of inert nonwettable material such as a plastic material. This tube is dipped by the pipette into the sample fluid and a pump 3,484,206 Patented Dec. 16, 1969 device of known form sucks up a pre-determined quantity thereof. The pipette and tube now rise from the sample fluid and move to the receptacle into which the said quantity is discharged, with or without the addition of a quantity of reagent solution.

If however the amount of fluid extracted from the sample tube is only a small fraction of a cubic centimeter the droplet thereof retained on the end of the pipette tube by surface tension, may have a volume which is appreciable compared with the total amount of fluid extracted from the sample tube. In addition the droplet may vary in volume.

We therefore arrange that the end of the pipette tube wipe over the edge of the sample tube after extracting therefrom the pre-determined amount. This substantially removes any droplet left on the end of the pipette tube, and greatly increases the accuracy of operation of the device.

A similar wiping action may take place over the edge of the receptacle into which the sample is discharged.

Reference should now be made to the accompanying drawings, in which:

FIG. 1 shows a circular rig embodying our invention,

FIG. 2 shows means for replacing a pipette,

FIG. 3 is a table form of trough and receptacle sup- P FIG. 4 is a table form of tube and receptacle support,

FIG. 5 is a single ring form of support for multiple sampling,

FIG. 6 is a band form of tube, trough or receptacle support.

The rib shown in FIG. 1 is for the purpose of receiving a plurality of biological samples in tubes in an outer ring container and transferring a measured quantity of each sample to a receptacle on an inner ring holder, with the addition of a quantity of reagent, each sample is collected into a tube 1 which is dropped into a hole in an outer ring container 2, this container being located on a table 3.

The latter is rotatably indexed by a pin and slot mechanism driven by a motor (not shown) located in the base 4 of a chassis 5, so as to bring tube and receptacle pairs successively to a predetermined position.

The motor also drives a series of cams which act on a pipette arm 6 pivoted on a shaft 7. The arm carries a short length of flexible plastic tubing 8 held in a replaceable clip 9, the pipette being connected by flexible tubing 10 to a metering pump 11. The pipette is guided so that its end dips first into a tube 1. The pump is operated to extract a predetermined quantity of sample. The pipette end now wipes over the edge of the tube to remove any droplets, rises, and enters one of the receptacles 12 located in an inner ring 13. These receptacles are tilted inwards with respect to the top of the ring so that the ring and its contents can be placed directly in a centrifuge. The pipette discharges the sample into the receptacle, together with a metered quantity of a reagent or cleaning fluid derived from a bottle 14 via a pipe 15 and pump 11. Finally the pipette once more wipes over the edge of the receptacle to remove any droplet, and the carrying arm returns it to a start position. The two rings index round to bring the next tube-receptacle pair within reach of the pipette, and the cycle is repeated until all the receptacles have received a charge.

In one form of sample treatment, the inner ring 13 is removed by hand from the rig shown, rotated for a required period in a centrifuge, and then transferred to a second rig similar to that shown in the drawing, except that no outer ring is fitted. The pipette of the second rig now injects a metered quantity of a reagent into each receptacle without transferring any fluid to a further receptacle.

The ring is once more transferred to a third rig similar to the one shown in the drawing, together with an outer ring furnished with tubes. This time the pipette dips into the receptacles in the inner ring, extracts a quantity of supernatant liquid from each, and transfers it to a corresponding tube in the outer ring. Finally the outer ring with its tubes is placed on another rig associated with a measuring device, and the pipette and pump thereof extract a quantity of fluid from each tube in turn, wash out a cuvette on the measuring instrument, fill the cuvette, and allow the instrument to measure a particular feature of the fluid before emptying the cuvette and recommencing the cycle. A description of this process is given in copending US. patent application No. 550,876 filed May 3, 1966.

If the reagent to be added to any particular set of samples is to be changed, a second pipette 16, pump 17 and bottle 18 may be located on the rig; the first pipette is removed from the arm 6 and replaced by the second, the change-over occupying only a very short time.

The pipette may be located on its arm with its end substantially vertical, or it may be tilted so as to enter the slanting receptacles in the inner ring. For rigs in which no reagent is to be added, the reagent bottle is omitted, the pump mechanism being suitably modified. In this connection it will be understood that the pump mechanism is itself interlocked with the motor cams and controlled thereby, so that it operates only at the required time. The throw or delivery of the pump can be adjusted to suck up or deliver any desired quantity of sample or reagent.

FIG. 2 shows how a pipette is attached to its arm. The clip 9 carries a length of small-bore flexible plastic tube 8, attached to another flexible tube 10. The clip 9 has a slot 21, and slides over the end of the arm 6, the slot passing around a screw 20 having a knurled head. When the screw is manually loosened the pipette 8 and its clip 9 can be slid ofl the arm and replaced by another.

Should it be necessary to deal with a larger number of similar samples than can be dealt with by a ring, the latter may be replaced by a flexible endless belthaving pockets or holes for receiving the tubes or receptacles carrying the samples.

All the rings or containers have slots registering with a spline or splines on the tables of each rig so that every sample can be recognised at any rig by its position thereon.

FIGURE 3 shows a table form of support 27 for taking simultaneously measured quantities of a sample, adding different reagents to each quantity, and transferring them to separate tubes for submission subsequently to different tests. Each sample is placed in a narrow trough 41, carried on the table 27. Near each trough is a plurality of tubes 22, and the table is indexed along to bring each trough and its associated tubes under a plurality of pipettes 23. Each pipette is connected to a different reagent, so that after passing the pipettes the tubes 22 carry portions of the same sample, but with diflerent reagents.

FIG. 4 is an alternative to FIG. 3. A row of sample receptacles 44 containing the same (or different) fluid is located on a table 29 adjacent a row of tubes 25. The table is indexed past a set of pipettes 26 which may be connected to and supply different (or the same) reagents.

FIG. shows a circular form of table with troughs and tubes as in FIGURE 3, though of course tubes and receptacles as in FIG. 4 may be fitted. In this arrangement shown, two sets of pipettes 30, 31 are provided (more sets may of course be used if required), acting sequentially on the tubes as they pass beneath them.

FIG. 6 shows a belt arrangement suitable for use in connection with a large number of samples. Either a single belt or two belts 34, 35, one inside the other as Shown, y e used: The top half of the fig re sh ws the belts equipped with troughs 32 and tubes 33 as in FIG. 3, and the bottom half with receptacles 38 and tubes 33 as in FIG. 4. The two arrangements are of course alternatives. Filled troughs and empty tubes may be aflixed to the belts at point A, passed under one or more pipettes 39, and removed at point B. Alternatively the tubes with their samples plus reagents may pass through a measuring instrument While still on the belt. there being means such as holes in the belt to allow the passage of a light beam for evaluation of the light transmission of the fluids in the tubes. The belts are shown as passing over supporting and driving rollers 37.

All arrangements are such than an indication is always available as to the patients name, kind of sample, batch number, test result and the like.

Any pipette subsequent to the first may only add a reagent to a sample quantity without transferring it to a further receptacle, or it may extract a predetermined quantity for test purposes.

I claim:

1. Chemical sampling and treating apparatus for acting successively on a series of samples and for preparing said samples for centrifuging comprising:

a pipette tube;

a pump coupled to said pipette;

a first container in the form of a ring carrying a first plurality of sample receptacles;

a second ring-shaped container located within said first ring container and carrying a second plurality of receptacles;

means for intermittently moving said first container to move one of said first receptacles into registration with said pipette;

an arm holding said pipette tube and movable to move said pipette tube in apredetermined path and means moving said arm to move said pipette through said path, said path being in a direction to dip said pipette into one of said first plurality of receptacles which is in registration therewith, to withdraw said pipette from said receptacle and wipe said pipette over the edge of said receptacle to remove any droplet carried by said pipette during withdrawal, and then move said pipette to one of said second plurality of receptacles; and

means for actuating said pump to extract fluid from said receptacle and into said pipette when said pipette is dipped into one of said first plurality of receptacles and to transfer said extracted fluid to one of said second plurality of receptacles.

2. Apparatus according to claim 1, wherein said receptacles carried by said second container are tubes, the longitudinal axes of said tubes being inclined with respect to the axis of said second ring so that said second ring together with said tubes can be transferred for use with a centrifuge.

References Cited UNITED STATES PATENTS 2,653,083 9/1953 Wanzer et al. 23253 2,879,141 3/1959 Skeggs 23-253 3,038,340 6/1962 Isreeli.

3,192,968 7/1965 Baruch et al. 23-259 XR 3,327,535 6/ 1967 Sequeira 73425.6 XR FOREIGN PATENTS 671,714 5/ 1952 Great Britain.

MORRIS O. WOLK, Primary Examiner R. M. REESE, Assistant Examiner U.S. Cl. X.R, 23*259; 73-423 

